# include <stdio.h>

int main(int argc, const char *argv[]) {
    int a = 0;
    scanf("%d", &a);
    if (a < 60) {
        printf("NO PASS\n");
    } else if(a >= 60 && a < 80) {
        printf("C\n");
    } else if(a >= 80 && a < 90) {
        printf("B\n");
    } else if(a >= 90 && a <= 100) {
        printf("A\n");
    } else {
        printf("error point\n");
    }
    return 0;
}
